[diverjohn (OP)]

A few years ago I heard an interview with a Dr Baker then at the Howard Hughes medical something or other, and his claim to fame was that he had created a pill intended to be consumed by a runner. This pill would trick the skeletal muscles into burning more fat than usual during a long run and thus delaying The Wall, or the point where the runner depletes his store of glucose normally used to fuel the muscles. I've heard no more, and have been unable to find anything from a simple Google search.
Anyone in the audience heard of this and can fill me in on where it went?

[RidaChat]

I think the marathon run is enough to burn fat. Hmmm no need to make it doubled. Maybe you have'nt heard  or search it because this is not good to heart.

[evan_au]

A paper published this year found that your microbiome has an affect on marathon performance.
- They looked at the microbiome of people who ran the 2015 Boston Marathon, before and after the race.
- They found that one of the bacteria more common in marathon runners helped mice run farther on a treadmill.
- They also found that one of the metabolic products produced by this bacteria also helped mice run further before they hit "the wall".

As I understand it, this improved performance is occurs without increasing the energy consumed - the bacteria just helps them consume the energy more efficiently.

See: https://news.harvard.edu/gazette/story/2019/06/performance-enhancing-bacteria-found-in-the-human-microbiome/

But don't you want something that degrades marathon performance, so you burn more fat?

[Bored chemist]

"Is there a way to burn more fat during a marathon run?"
Carry a rucksack full of rocks.